Mask assembly



FIG. 1 is a front perspective view of a mask assembly showing our new design;

FIG. 2 is a front view thereof;

FIG. 3 is a rear view thereof;

FIG. 4 is a top view thereof;

FIG. 5 is a bottom view thereof;

FIG. 6 is a left side view thereof, with the right side view being a mirror image thereof; and,

FIG. 7 is a rear perspective view thereof.

Where included, the use of stippling (e.g., for the cushion) indicates a contrasting material with the adjacent line-shaded portion of the mask assembly, e.g., the frame and shroud.

The dotted lines represent the border between claimed and unclaimed subject matter and do not form part of the claimed design.

The dashed, broken lines shown throughout the views represent the portions of the mask assembly, which form no part of the claimed design. 

CLAIM The ornamental design for a mask assembly, as shown and described. 